Labor has used its dramatic about-face on migration policy to challenge the Coalition to back its plan to send asylum seekers to Malaysia.

Immigration Minister Chris Bowen today introduced legislation to excise the mainland from the migration zone, in a move that would strip away any legal advantage people get if they bypass Christmas Island.

He concedes the move marks a big shift in his position compared with comments he made in 2006 when he described a similar piece of legislation as a "hypocritical and illogical bill".

"Yes, this is a change of position," Mr Bowen told AM this morning.

"Yes, you can go back and look at what I said as an Opposition backbencher a long time ago and compare it to what I'm doing now as Minister for Immigration - that's perfectly legitimate."

In 2006, Mr Bowen said of a similar bill: "If it is passed today, it will be a stain on our national character".

Mr Bowen says today's legislation came out of the expert panel on asylum seekers, which recommended the mainland be excised as part of the Government's border protection policy.

"I've changed the Labor Party's position and I changed my mind, based on the evidence, based on the recommendations of the Houston panel, and based on the evidence that this will save lives," Mr Bowen said.

"We'll do what it takes to save lives, even if it means taking positions that we've opposed before, even if it means people trawling through our speeches and pointing out what we said before, because we're determined to save lives.

"Now I actually would hope the Liberal Party would take a similar approach."

Refusing to budge

The Government is trying to pressure the Coalition into supporting a deal with Malaysia, which would involve sending 800 asylum seekers to that country in return for accepting 4,000 people who have had their refugee claims processed.

But the Coalition is refusing to budge on the issue, arguing that the arrangement does not have strong enough safeguards in place to protect human rights.

"The Minister has been told by the Houston panel - which he has given great credence to - to go and fix the Malaysian people swap," Mr Morrison told AM.

"Now he hasn't tried to fix it. He hasn't fixed it.

"The legally binding protections aren't in place for that arrangement.

"(Mr Bowen) can't just blame the Coalition because he couldn't be bothered going back to Malaysia and to get the legally binding protections that are necessary at the very least to ensure this as a possible measure."

Mr Bowen says the Government remains in negotiations with Malaysia, but says any deal would be impossible to implement without the support of either the Greens or the Opposition.

On the issue of excising the mainland from the migration zone, Mr Morrison says the Coalition still needs to consider the legislation before declaring its support for the move.

But he doubts it will work as a deterrent, arguing that Labor "neutered the excision policy" in March when it gave asylum seekers who arrived by boat the same avenues for an independent review through the refugee tribunal as those who arrived by plane.